(1) Field of the Invention
The present invention relates to a developer unit for use in an image forming apparatus such as a copier, printer, facsimile machine, etc., for performing image forming based on the electrophotographic process, in particular is directed to removal of the toner stuck on the toner layer metering blade in a developer unit using a mono-component developer.
(2) Description of the Prior Art
The developer unit for a mono-component developer that contains no carrier, not only has a simple configuration and hence can be made compact because of absence of carrier particles but also offers the advantages of low cost and easy maintenance. In particular, since a non-magnetic mono-component toner that does not contain magnetic toner, does not use a magnetic roller, it is possible to provide an inexpensive, compact, developer unit creating clear images. Further, since the toner does not contain any magnetic material, toner of this type is suitable to be utilized for color imaging. When classifying mono-component developer units based on their developing methods, there have been two known methods, one for the contact developing system for performing development by being in contact with the photoreceptor, and the other for the non-contact developing system for performing development by being not in contact with the photoreceptor.
Generally, in a mono-component developing method in which either the toner is magnetic or non-magnetic, and either the system is in the contact type or non-contact type, a thin layer of the electrified mono-component toner is formed on a developer support, and this thin layer is conveyed with the rotation of the developer support to the developing position where the toner opposes the photoreceptor with a latent image formed thereon, whereby the latent image on the photoreceptor is made into a visible (developed) image. In this case, in order to obtain high quality images, the way that a stable thin toner layer, uniformly charged, and with a uniform thickness is formed on the developer support is very important.
Typically, electrification and formation of the thin toner layer on the developer support are performed using a toner layer metering blade which is pressed against the developer support with a predetermined pressure. Charging and formation of the thin toner layer may be beneficial in the initial stage of use, but toner may stick to the toner layer metering blade after a long period of use, failing to form a preferable toner layer, causing image degradation. Actually, continuous abutment of the toner layer metering blade against the developer support at the predetermined pressure will cause the toner to adhere (stick) to the blade surface within the abutment nip between the toner layer metering blade and the developer support and therearound, due to frictional heat, the pressure and/or environmental factors such as the temperature in the machine and the like.
Such buildups are slight and formed as a thin film at their initial stage, posing no problem in image forming, but will grow as the machine is used, soon presenting adverse effects in the image.
Actually, the stuck buildups deteriorate toner electrification performance by the toner layer metering blade, and clog the toner inflow opening between the blade and the developer support, forming physical irregularities on the surface in contact with the developer support, which causes widespread or local reduction in thickness of the toner layer or excessive toner passing (increase in toner layer thickness), making it impossible to form a uniform and even toner layer. As this result, light print, local white lines, and local black streaks (when monochrome) and the like arise on the image.
In order to solve this problem, some methods of cleaning the stuck toner on the toner layer metering blade have been proposed. For example, Japanese Patent Application Laid-Open Hei 7 No.163440 discloses a stuck toner removal member which is slidable between the developer support and the toner layer metering blade and removes stuck toner as it slides. This publication further discloses another configuration wherein the toner layer metering blade is configured so as to slide up and down along the developer support and sliding the toner layer metering blade up and down removes the stuck buildups.
Japanese Patent Application Laid-Open Hei 5 No.127509 discloses another configuration wherein with the toner layer metering blade fixed to a movement driver, the movement driver is actuated so as to vary the abutment position between the toner layer metering blade and the developer roller, thus preventing toner from sticking to the toner layer metering blade.
As in Japanese Patent Application Laid-Open Hei 7 No.163440, inserting and sliding a removal member between the developer support and the toner layer metering blade abrades the toner layer metering blade surface as well as the developer support and may damage the both.
In general, the toner layer metering blade is pressed against the developer support with a linear pressure of some tens of gf/cm to some hundreds of gf/cm, depending on the configuration. It is not so easy to slide the inserted removal member between the toner layer metering blade and the developer support without damaging them. In the configuration of the above disclosure, the edges of the removal member are finished with precision, needing a high cost. Further, in order to avoid damage, it is necessary to slide the removal member without its being scratched as it moves and move it straightly keeping its face angle constant.
That is, the method described in the above publication, makes it possible to remove stuck buildups from the toner layer metering blade, but are liable to damage the developer support surface as well as the toner layer metering blade and also causes a cost increase. By any means, moving the removal member whilst keeping it in contact with both elements may cause a certain amount of damage.
Further, in the case of Japanese Patent Application Laid-Open Hei 5 No.127509, a movement driver means to which fixing the toner layer metering blade is fixed is additionally needed, leading to a sharp cost increase because of the necessity of the controller means for this movement driver means and needing extra space for setting it. Therefore, application of this method to existing apparatus is limited. In accordance with the method disclosed in the configuration of the above publication, since the toner layer metering blade is moved rubbing the developer roller when the abutment position between the toner layer metering blade and the developer roller shifts, it is not preferred because there is a risk of damaging both the developer roller and the toner layer metering blade.
In order to solve the above problems, the present inventors hereof have studied intensively and found that instead of using the technique of inserting a cleaning element between the developer support and the toner layer metering blade, adoption of a configuration in which a cleaning element is arranged on the backside of the toner layer metering blade, i.e., the side opposite to the surface in contact with the developer support so that the cleaning element can frictionally move relative to the toner layer metering blade will lower the risk that the cleaning element might cause damage, as it rubs, to the toner layer metering blade surface and the developer support surface on which the metering blade abuts, and will remove the stuck toner on the toner layer metering blade as well as preventing the occurrence of stuck buildups.
At the toner layer metering blade, if the toner stops moving at the same place, the same mass of toner continues to be stressed, soon becomes transmuted, forming stuck buildup. Even in such cases, the stationary toner residing around the blade edge can be removed and eliminated by rubbing of the cleaning element around the blade edge from the backside of the blade, instead of rubbing the blade from the developer support side.
Thus, it is possible to eliminate the situation where the same mass of toner is being stressed by remaining at the. same place, resultantly it is possible to delay the emergence of stuck buildups and the growing of them. Further, even if the stuck buildups have already grown, being projected from the blade edge, parts of the buildups which can be seen from the backside edge of the blade, may be removed from the blade backside. Because the stuck buildups are unified with the buildups on the blade abutment side (opposing the developer support), the stuck buildup can be removed altogether including that part on abutment surface side.
That is, when a stuck buildup has already formed, instead of rubbing the buildup at the abutment nip around which the buildup sticks most firmly, areas to which the buildup sticks less firmly may and should be rubbed because the stuck buildup is one-piece. Accordingly, areas in some part away from the nip or the portion projected from the blade distal part (edge) are rubbed by a force acting in the direction different from that of the blade""s pressing force, so that the stuck buildup can be removed with a small force. As a result, it is possible to eliminate and prevent white lines, black streaks, light images which attributes to stuck buildups on the blade.
As stated above, this blade backside scraping method using a cleaning element, compared to the method of interposing a cleaning element between the developer support and the blade, is not only effective in preventing damage to the abutment surface of the blade and developer support, but also does not need to produce a force opposing the urging force of the blade on the developer support, hence allows the cleaning element to scrape with a low energy.
The direction of sliding movement of the cleaning element can be selected from two types, one for widthwise movement in which the cleaning element is moved from the fixed end (supported end) side of the blade to the free end (abutment edge) side and the other type for lengthwise movement in which the cleaning element is slid in the lengthwise direction of the blade. The configurations of cleaning elements will be explained separately for the blade widthwise movement type and for the blade lengthwise movement type.
First, in the case of blade widthwise movement type, the cleaning element is slid from the fixed end (supported end) side of the blade to the free end (abutment edge) side, so as to thrust (or draw) out stuck buildups or adhering substances in the direction of open space, thus making it possible to effectively remove the stuck buildups and adhering substances. Further, when the direction of abutment of the blade is in the leading direction, the cleaning element is able to act on the buildups or stationary toner with a force in the direction opposite to that acting on the buildups by the toner flowing in from the upstream side while the developer support normally rotates, thus making it possible to remove them effectively.
The dimension of the cleaning element in the lengthwise direction of the blade is not particularly limited. For example, the cleaning element may have a strip-like configuration, i.e., with a long side in the vertical direction, or may have a horizontal side approximately equal to the blade length. For a strip-like configuration, the cleaning element needs to be moved along the length of the blade. When the cleaning element is adapted to have a horizontal side approximately equal to the blade length, the full length of the blade can be cleaned all at once, thus making it possible to effectively clean the blade by a single (or some times of) vertical movement (blade widthwise movement) which is preferable.
The shape of the cleaning element is not particularly limited, but adoption of a sheet-like configuration, particularly, thin plate-like sheet configuration, makes the cleaning element simple, and makes it possible to efficiently scrape the stuck buildups by the edges of the sheet-like element.
Both horizontal side ends of the cleaning element may be formed linearly or curved. When the ridgelines or edges (or sides if they are linear) are not in parallel with the direction of movement of the cleaning element (the direction of movement from the fixed end side of the blade to the free end side), but are inclined, it is possible to prevent the edges, i.e., ridgelines of the cleaning element from rubbing the same point on the surface of the developer support and the backside of the blade while the cleaning element moves. Therefore, it is possible to prevent this scraping movement from damaging the developer roller surface and the blade edge part.
If the width, or dimension of projection from the proximal end, of the cleaning element, perpendicular to the lengthwise direction thereof is varied, the side edges of the sheet-like cleaning element can be inclined relative to the direction of sliding movement (the direction of movement from the fixed end side to the distal end side of the blade). Therefore, the edge of the cleaning element abuts a stuck buildup at only a point (only some points), so that the applied force on the cleaning element can be concentrated on that point while a force having a different force component from the direction of movement of the cleaning element can be applied to the buildup. This makes it possible to remove stuck buildups more efficiently. In practice, stuck buildups are clustered or entangled to each other, so instead of applying a removal force on the cluster, all at once, application of the removal force locally and concentratively on part of the buildup, makes it possible to effectively remove the buildup at that part.
Since the abutment point (cleaning point) of the edge of the cleaning element against the distal part of the blade continuously moves as the cleaning element moves down, the buildups can be removed successively. During this process, since the point of cleaning moves from the side where removal has been done to the unremoved side, it is possible to make the force act from the side where removal has been done, and hence stuck buildups can be efficiently peeled off.
In this case, if the cleaning element is formed with its width or the dimension of projection from its proximal end on the left being a mirror image of that on the right, (xe2x80x98on the leftxe2x80x99 and xe2x80x98on the rightxe2x80x99 are referred to with respect to the lengthwise direction of the cleaning element), the forces acting on the cleaning element during its sliding for cleaning, also become axially symmetrical, therefore the warp and distortion of the cleaning element can be prevented or reduced. As a result, a thin and soft sheet-like material can be used for the cleaning element, which is able to further lower the risk of the cleaning element damaging the developer support and the blade.
When the length, or the horizontal dimension of the cleaning element is approximately equal to that of the blade, the cleaning effect on the blade becomes symmetrical with respect to the midpoint of the axis of the developer support. Therefore, if an image defect occurs due to cleaning defects attributing to the shape or distortion of the cleaning element, the image defect will be also symmetrical and hence inconspicuous.
When the width or dimension of projection from its proximal end of the cleaning element varies linearly, stuck buildups can be removed locally and successively, and because of the linear variation in width, the same force (the horizontal and vertical force components) not varying in its direction can be applied at any position, thus making it possible to remove stuck buildups uniformly.
The configuration of the cleaning element is not particularly limited as long as it can frictionally slide along the toner layer metering blade and remove stuck buildups. However, when a soft and flexible member or brush-like member attached to an elastic thin plate-like support is adopted, a strong enough force in the urging direction can be applied through the contact area still there is no risk of damaging the developer support.
Next, the configuration of the cleaning element of the blade lengthwise movement type will be explained. In the case of the blade lengthwise movement type, since the cleaning element will not be moved in the widthwise direction, the dimension in the widthwise direction of the cleaning element has to be at least large enough to be in contact with the distal end of the blade while there is no need to have a length equal to the blade length and a strip-like configuration can be used.
The thickness of this cleaning element is not particularly limited. Similarly to the widthwise movement type, a sheet-like member, a soft and flexible member or brush-like member attached to an elastic thin-plate like support can be adopted.
In the case of the blade lengthwise movement type, both side edges of the cleaning element with respect to the lengthwise direction function as the scrapers acting on the blade. Even if the sectional shape of the cleaning element is cut straight a certain degree of buildup removal effect can be obtained, but if the cleaning element is provided at both sides with sloping portions toward the directions of movement, the buildup removal effect can be more enhanced. As examples of the slopes, a sheet-like cleaning element may be formed with obtusely angled tabs at both sides thereof, or may be formed with curved tabs at both sides thereof. Further, both sides may be bent at right angles.
Concerning the shape of the distal edge of the sloping tab, other than that particularly unshaped, the edge portion may be cut along the contact angle with the toner layer metering blade forming a knife-edge configuration. Alternatively, the edge may be formed with a knife-edge configuration which will come in point contact with the blade or share a smaller contact area with the blade. Further, it is possible to employ a wedge-shaped edge configuration which is thick at the proximal side and is tapered to a distal edge toward the direction of movement. In either case, the buildup removal effect can be enhanced.
It is also possible to enhance the buildup removal effect by providing jagged edges on both sides of the cleaning element. Examples of formation of jagged edges include a saw-toothed configuration, wavy configuration and rectangular wavy configuration.
As another configuration, a plurality of slots in parallel with the edges on both sides may be formed in the cleaning element. In this case, provision of the slots enables the toner and other particles existing between the toner layer metering blade and the cleaning element to be discharged while the cleaning element is being slid, whereby it is possible to remove an elastic thin plate-like support buildups in a more effective manner.
The movement of the cleaning element in the lengthwise or widthwise direction can be carried out manually or by various drive mechanisms. In the case of using a drive mechanism, the cleaning operation can be effected at various timings in association with the conditions or operations of the image forming apparatus. For example, in an image forming apparatus having a counter means capable of counting, at least one of the number of image formed printouts, the operating time and the number of rotations of the developer support, it is preferred that the apparatus is controlled so that the cleaning operation is performed when the counted value on the counter means reaches the predetermined value.
In this way, periodic execution of cleaning the toner layer metering blade makes it possible to remove stuck buildups and prevent their growth, or emergence of a buildup itself over a long period. As a result, excellent images free from white lines, high-density streaks (black lines), light images, which all accompany stuck toner on the toner layer metering blade, can be obtained over a long term.
Further, in a developer unit which is applied to an image forming apparatus including a controller for controlling the image forming process conditions and the like by effecting image adjustment so as to provide optimal printed-out images when power is activated, when the number of printouts reaches the predetermined value, when the predetermined time elapses and/or when the machine has recovered from the energy saving mode, the controller controls the cleaning element so as to perform the cleaning operation before or in parallel with the image adjustment. This configuration enables the image adjustment to be performed with the image degradation which would occur due to stuck toner on the toner layer metering blade, whereby it is possible to obtain excellent images. Further, since the toner layer metering blade can be cleaned periodically in time with the image adjustment, it is possible to maintain beneficial images over a long period.
By providing a system in which the cleaning element is operated to clean the distal part of the toner layer metering blade every time the toner container cartridge is replaced to supply fresh toner to the developer hopper, the cleaning can be done approximately periodically. Further, since when fresh toner is re-supplied, little stresses arise while cleaning the blade, cleaning at this timing is also effective in reviving the electrifying function of the blade. At the timing of toner replenishing, the toner in the developer hopper is almost used up. That is, the amount of toner in the developer hopper is relatively low (the hopper is not full of toner), so that the cleaning element can perform its cleaning operation without any obstacles and hence can efficiently remove stuck substances around the distal part of the blade.
By providing a system in which this cleaning element is integrated with the toner replenishing cartridge for replenishing fresh toner so as to enable cleaning when the toner replenishing cartridge is attached, it is possible to perform cleaning approximately periodically at the timing of replacement of the toner cartridge. Since the cleaning element is provided for the toner replenishing cartridge, there is no need to provide a cleaning element on the developer hopper side, and hence there is no need to provide a special configuration on the developer hopper side.
As an arrangement of the cleaning element in the developer unit, the cleaning element may be attached to the agitator in the unit so that the cleaning element will clean the distal part of the toner layer metering blade with the agitating operation of the agitator. In this configuration, the cleaning element can be made to function as a mixing element, so that the blade (backside) can be continuously cleaned in time with mixing. Further, since the toner cluster or stuck buildups removed by cleaning can be agitated and dispersed as is in the developer hopper, it is possible to lower the risk of the buildups flowing into the blade abutment portion.
The above toner layer metering blade and cleaning element can be applied to various developer units having different types of toner. In particular, this configuration is favorably applied to a developer unit of a non-magnetic mono-component toner development type.
Thus, the present invention is configured as above and the main features are described as follows:
In accordance with the first aspect of the present invention, a developer unit includes: a toner layer metering blade disposed in pressure contact with the developer support surface for adjusting the thickness of the toner layer on the developer support surface; and a cleaning element for removing stuck toner around the abutment edge of the toner layer metering blade against the developer support, and is characterized in that the cleaning element is arranged on the backside of the toner layer metering blade, the side opposite to the surface in contact with the developer support and can be frictionally slid from the fixed edge to the distal edge of the toner layer metering blade.
In accordance with the second aspect of the present invention, the developer unit having the above first feature is characterized in that the length or horizontal dimension of the cleaning element is set approximately equal to the length of horizontal dimension of the toner layer metering blade.
In accordance with the third aspect of the present invention, the developer unit having the above first feature is characterized in that the cleaning element is of a sheet-like configuration.
In accordance with the fourth aspect of the present invention, the developer unit having the above first feature is characterized in that the both the sides or ridgelines at both horizontal ends of the cleaning element are inclined with respect to the direction of movement of the cleaning element.
In accordance with the fifth aspect of the present invention, the developer unit having the above first feature is characterized in that the cleaning element is of a sheet-like configuration and the width, or dimension of projection from the proximal end, of the cleaning element varies along the long side of the toner layer metering blade.
In accordance with the sixth aspect of the present invention, the developer unit having the above fifth feature is characterized in that the cleaning element has an axial symmetrical shape about the medial line with respect to the length thereof with its width or the dimension of projection from its proximal end on the left is the mirror image of that on the right.
In accordance with the seventh aspect of the present invention, the developer unit having the above sixth feature is characterized in that the width or dimension of projection from its proximal end of the cleaning element varies linearly.
In accordance with the eighth aspect of the present invention, a developer unit includes: a toner layer metering blade disposed in pressure contact with the developer support surface for adjusting the thickness of the toner layer on the developer support surface; and a cleaning element for removing stuck toner around the abutment edge of the toner layer metering blade against the developer support, and is characterized in that the cleaning element is comprised of a soft and flexible member applied on an elastic thin plate-like support, is arranged on the backside of the toner layer metering blade, the side opposite to the surface in contact with the developer support and can be frictionally slid from the fixed edge to the distal edge of the toner layer metering blade.
In accordance with the ninth aspect of the present invention, a developer unit includes: a toner layer metering blade disposed in pressure contact with the developer support surface for adjusting the thickness of the toner layer on the developer support surface; and a cleaning element for removing stuck toner around the abutment edge of the toner layer metering blade against the developer support, and is characterized in that the cleaning element is comprised of a brush-like member applied to an elastic thin plate-like support, is arranged on the backside of the toner layer metering blade, the side opposite to the surface in contact with the developer support and can be frictionally slid from the fixed edge to the distal edge of the toner layer metering blade.
In accordance with the tenth aspect of the present invention, the developer unit having the above first feature is characterized in that the cleaning element is integrally attached to the toner container cartridge for supplying fresh toner.
In accordance with the eleventh aspect of the present invention, the developer unit having the above first feature is characterized in that the cleaning element is attached to an agitating element inside the developer unit so as to clean the distal part of the toner layer metering blade in time with the agitating action of the agitating element.
In accordance with the twelfth aspect of the present invention, a developer unit includes: a toner layer metering blade disposed in pressure contact with the developer support surface for adjusting the thickness of the toner layer on the developer support surface; and a cleaning element for removing stuck toner around the abutment edge of the toner layer metering blade against the developer support, and is characterized in that the cleaning element is arranged on the backside of the toner layer metering blade, the side opposite to the surface in contact with the developer support and can be frictionally slid along the long side of the toner layer metering blade.
In accordance with the thirteenth aspect of the present invention, the developer unit having the above twelfth feature is characterized in that the cleaning element can be reciprocated or vibrated along the long side of the toner layer metering blade.
In accordance with the fourteenth aspect of the present invention, the developer unit having the above twelfth feature, includes: a toner layer metering blade disposed in pressure contact with the developer support surface for adjusting the thickness of the toner layer on the developer support surface; and a cleaning element for removing stuck toner around the abutment edge of the toner layer metering blade against the developer support, and is characterized in that the cleaning element is of a sheet-like configuration, is arranged on the backside of the toner layer metering blade, the side opposite to the surface in contact with the developer support and can be frictionally slid along the long side of the toner layer metering blade.
In accordance with the fifteenth aspect of the present invention, the developer unit having the above fourteenth feature is characterized in that the sheet-like cleaning element has a pair of sloping tabs on both sides thereof with respect to the direction of movement, the edges of the sloping tabs are frictionally slidable along the toner layer metering blade.
In accordance with the sixteenth aspect of the present invention, the developer unit having the above fourteenth feature is characterized in that each of both side parts of the sheet-like cleaning element is thick at the proximal side and is tapered to a distal edge toward the direction of movement.
In accordance with the seventeenth aspect of the present invention, the developer unit having the above fourteenth feature is characterized in that both side parts of the sheet-like cleaning element with respect to the direction of movement are formed with jagged edges.
In accordance with the eighteenth aspect of the present invention, the developer unit having the above seventeenth feature is characterized in that both side parts of the sheet-like cleaning element with respect to the reciprocating direction are formed with wavy jagged edges.
In accordance with the nineteenth aspect of the present invention, the developer unit having the above seventeenth feature is characterized in that both side parts of the sheet-like cleaning element with respect to the reciprocating direction are formed with saw-toothed jagged edges.
In accordance with the twentieth aspect of the present invention, the developer unit having the above seventeenth feature is characterized in that both side parts of the sheet-like cleaning element with respect to the reciprocating direction are formed with rectangular wavy jagged edges.
In accordance with the twenty-first aspect of the present invention, the developer unit having the above fourteenth feature is characterized in that the sheet-like cleaning element has slots in parallel with the both side edges with respect to the reciprocating direction.
In accordance with the twenty-second aspect of the present invention, the developer unit having the above seventeenth feature is characterized in that the sheet-like cleaning element has slots in parallel with the both side edges with respect to the reciprocating direction, and the edge of the longest side of each slot is folded forming a folded portion.
In accordance with the twenty-third aspect of the present invention, the developer unit having the above twenty-second feature is characterized in that the edge of the longest side of each slot is folded and the folded portion is formed with a jagged edge.
In accordance with the twenty-fourth aspect of the present invention, a developer unit includes: a toner layer metering blade disposed in elastic contact with the developer support surface for adjusting the thickness of the toner layer on the developer support surface; and a cleaning element for removing stuck toner around the abutment edge of the toner layer metering blade against the developer support, and is characterized in that the cleaning element is comprised of a soft and flexible member applied to a thin plate-like support, is arranged on the backside of the toner layer metering blade, the side opposite to the surface in contact with the developer support and can be frictionally slid along the long side of the toner layer metering blade.
In accordance with the twenty-fifth aspect of the present invention, a developer unit includes: a toner layer metering blade disposed in elastic contact with the developer support surface for adjusting the thickness of the toner layer on the developer support surface; and a cleaning element for removing stuck toner around the abutment edge of the toner layer metering blade against the developer support, and is characterized in that the cleaning element is comprised of a brush-like member applied to a thin plate-like support, is arranged on the backside of the toner layer metering blade, the side opposite to the surface in contact with the developer support and can be frictionally slid along the long side of the toner layer metering blade.
In accordance with the twenty-sixth aspect of the present invention, the developer unit having the above first feature, which is applied to an image forming apparatus including a counter means capable of counting, at least one of the number of printouts, the operating time and the number of rotations of the developer support and is controlled so that the cleaning operation is performed when the counted value on the counter means reaches the predetermined value.
In accordance with the twenty-seventh aspect of the present invention, the developer unit having the above first feature, which is applied to an image forming apparatus including a controller for controlling the image forming process conditions and the like by effecting image adjustment so as to provide optimal printed-out images when power is activated, when the number of printouts reaches the predetermined value, when the predetermined time elapses and/or when the machine has recovered from the energy saving mode, wherein the controller controls the cleaning element so as to perform the cleaning operation before or in parallel with the image adjustment.
In accordance with the twenty-eighth aspect of the present invention, the developer unit having the above first feature, further includes a controller for controlling the operation of the cleaning element, wherein the controller controls the cleaning element so that the cleaning element cleans the distal part of the toner layer metering blade when the toner container cartridge is replaced to replenish fresh toner to the developer hopper.
In accordance with the twenty-nineth aspect of the present invention, the developer unit having the above eighth feature, which is applied to an image forming apparatus including a counter means capable of counting, at least one of the number of printouts, the operating time and the number of rotations of the developer support and is controlled so that the cleaning operation is performed when the counted value on the counter means reaches the predetermined value.
In accordance with the thirtieth aspect of the present invention, the developer unit having the above eighth feature, which is applied to an image forming apparatus including a controller for controlling the image forming process conditions and the like by effecting image adjustment so as to provide optimal printed-out images when power is activated, when the number of printouts reaches the predetermined value, when the predetermined time elapses and/or when the machine has recovered from the energy saving mode, wherein the controller controls the cleaning element so as to perform the cleaning operation before or in parallel with the image adjustment.
In accordance with the thirty-first aspect of the present invention, the developer unit having the above eighth feature, further includes a controller for controlling the operation of the cleaning element, wherein the controller controls the cleaning element so that the cleaning element cleans the distal part of the toner layer metering blade when the toner container cartridge is replaced to replenish fresh toner to the developer hopper.
In accordance with the thirty-second aspect of the present invention, the developer unit having the above ninth feature, which is applied to an image forming apparatus including a counter means capable of counting, at least one of the number of printouts, the operating time and the number of rotations of the developer support and is controlled so that the cleaning operation is performed when the counted value on the counter means reaches the predetermined value.
In accordance with the thirty-third aspect of the present invention, the developer unit having the above ninth feature, which is applied to an image forming apparatus including a controller for controlling the image forming process conditions and the like by effecting image adjustment so as to provide optimal printed-out images when power is activated, when the number of printouts reaches the predetermined value, when the predetermined time elapses and/or when the machine has recovered from the energy saving mode, wherein the controller controls the cleaning element so as to perform the cleaning operation before or in parallel with the image adjustment.
In accordance with the thirty-fourth aspect of the present invention, the developer unit having the above ninth feature, further includes a controller for controlling the operation of the cleaning element, wherein the controller controls the cleaning element so that the cleaning element cleans the distal part of the toner layer metering blade when the toner container cartridge is replaced to replenish fresh toner to the developer hopper.
In accordance with the thirty-fifth aspect of the present invention, the developer unit having the above twelfth feature, which is applied to an image forming apparatus including a counter means capable of counting, at least one of the number of printouts, the operating time and the number of rotations of the developer support and is controlled so that the cleaning operation is performed when the counted value on the counter means reaches the predetermined value.
In accordance with the thirty-sixth aspect of the present invention, the developer unit having the above twelfth feature, which is applied to an image forming apparatus including a controller for controlling the image forming process conditions and the like by effecting image adjustment so as to provide optimal printed-out images when power is activated, when the number of printouts reaches the predetermined value, when the predetermined time elapses and/or when the machine has recovered from the energy saving mode, wherein the controller controls the cleaning element so as to perform the cleaning operation before or in parallel with the image adjustment.
In accordance with the thirty-seventh aspect of the present invention, the developer unit having the above twelfth feature, further includes a controller for controlling the operation of the cleaning element, wherein the controller controls the cleaning element so that the cleaning element cleans the distal part of the toner layer metering blade when the toner container cartridge is replaced to replenish fresh toner to the developer hopper.
In accordance with the thirty-eighth aspect of the present invention, the developer unit having the above twenty-fourth feature, which is applied to an image forming apparatus including a counter means capable of counting, at least one of the number of printouts, the operating time and the number of rotations of the developer support and is controlled so that the cleaning operation is performed when the counted value on the counter means reaches the predetermined value.
In accordance with the thirty-ninth aspect of the present invention, the developer unit having the above twenty-fourth feature, which is applied to an image forming apparatus including a controller for controlling the image forming process conditions and the like by effecting image adjustment so as to provide optimal printed-out images when power is activated, when the number of printouts reaches the predetermined value, when the predetermined time elapses and/or when the machine has recovered from the energy saving mode, wherein the controller controls the cleaning element so as to perform the cleaning operation before or in parallel with the image adjustment.
In accordance with the fortieth aspect of the present invention, the developer unit having the above twenty-fourth feature, further includes a controller for controlling the operation of the cleaning element, wherein the controller controls the cleaning element so that the cleaning element cleans the distal part of the toner layer metering blade when the toner container cartridge is replaced to replenish fresh toner to the developer hopper.
In accordance with the forty-first aspect of the present invention, the developer unit having the above twenty-fifth feature, which is applied to an image forming apparatus including a counter means capable of counting, at least one of the number of printouts, the operating time and the number of rotations of the developer support and is controlled so that the cleaning operation is performed when the counted value on the counter means reaches the predetermined value.
In accordance with the forty-second aspect of the present invention, the developer unit having the above twenty-fifth feature, which is applied to an image forming apparatus including a controller for controlling the image forming process conditions and the like by effecting image adjustment so as to provide optimal printed-out images when power is activated, when the number of printouts reaches the predetermined value, when the predetermined time elapses and/or when the machine has recovered from the energy saving mode, wherein the controller controls the cleaning element so as to perform the cleaning operation before or in parallel with the image adjustment.
In accordance with the forty-third aspect of the present invention, the developer unit having the above twenty-fifth feature, further includes a controller for controlling the operation of the cleaning element, wherein the controller controls the cleaning element so that the cleaning element cleans the distal part of the toner layer metering blade when the toner container cartridge is replaced to replenish fresh toner to the developer hopper.